Airplane



Jam 15-, 1929, 1,698,849

' C. J. LEISY I AIRPLANE Filed June 16. 192'! s Sheets-Sheet 1 INVENTORC'Lif'foniJiLeLay A'r'ronucYs Jan. 15, 1929.

rt,v J. "LEls'Y AIRPLANE Filed June 16, 192'? s Sheets-Sheet 2 INVENTORI 02W O a .p wy

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I Patented Jan. 15,1929

UNITED STATES CLIFFORD J'. LEISY, OI OL EVELAND, OHIO, A SSIGNOR TO THEGLENN L MARTIN COM- PANY, OI CLEVELAND, OHIO, A CORPORATION OF OHIO.

AIRPLANE.

Application filed June 16, 1927. Serial No. 199,184.

This invention relates to improvements in airplanes, and particularly tostructural members for the framing of airplanes, and joints between suchmembers.

The interior surfaces of airplane struts, chords, tie members, etc. aresubject to rapld deterioration, particularly when made of a certainalloy of aluminum. In order to meet this difficulty it has been proposedto so form 1\ such structural members as to permitlnspection andtreatment of the interior surfaces thereof. The present invention insome of its aspects seeks to improve upon the means heretofore devisedfor that purpose.

One of the objects of the invention, therefore, is to provide for theinspection and treatment of internal surfaces of built up metalstructural members designed for use in airplanes.

Another object is to provide a structural member of the characterspecified, which is possessed of a high strength-weight ratio.

A further object is the provision in connection with structural membersof the kind mentioned, of means for easily and rigidly uniting suchmembers at their oints in airplanes. 7

Other objects and features of novelty Wlll appear as I proceed w1th thedescriptlon of that embodiment of the invention which, for the purposesof the present application, I have illustrated in the accompanyingdrawings, in which: Figure 1 is a perspective view of the frame- :m workof an airplane fuselage, comprislng structural members and ointsembodying my invention.

Figure 2 is a fragment of said framework, upon a larger scale, the viewbeing taken in 4a the direction of arrows A, Figure 1.

Figure 3 is a view partly in elevation and partly in section of thejoint shown in Figure 2, looking in the general direction of arrows B,Figure 2.

Similar reference characters refer to like parts throughout the views.

In the drawings a longron of the fuselage is shown at 1, being made upof four channel elements 2, havlng inclined side flanges .31, 2.Adjacent flanges 2 on the channel elements are spaced apart byoccasional spacing collars or washers 3, or 'by other means'to bementioned herein later. edge portion of each flange 2 an deflectedtoward the center line The is curled or of the corjoint shown there is asplice plate spacing responding channel elements, for the .purpose ofresisting crinklmgi, that is to say, local bending such as frequentlyoccurs in thin metal strips in the regions thereof which are mostsubject to compression or crushing strains.

Rivets or equivalent fastening means I extend through the spacingcollars or washers 3 to hold the flanges 2' together in spaced relation.Pairs of flanges which are diametrically opposite preferably have theirfastenings 3-4 in transverse alignment, while the fastenings for theremaining joints are preferably transversely opposite to each otherbeing arranged in staggered relation with respect to the first mentionedfastening-s.

n carrying out myinvention-I prefer to employ structural elements of thekind descriheul for all of the heavier frame parts of the machine, andin the drawings I have illustratml some of these parts at 1, l, 1", and1', the member 1 being vertical and perpendicular to the member 1, themember 1 being horizontal and perpendicular to the members 1 and 1 andthe member 1 being a diagonal cross strut. I prefer to employ analuminum alloy as the material for the channels 2.

The structural member herein illustrated lends itself very nicely to theformation of the oints at meeting points of the fuselage of the frame,as indicated in Figures 2 and 3. In Figure 2 the longron l is showncomposed of two parts spliced together. At the 8 arranged betweenflanges 2' connecting of the longron, being fastened with rivets 4 orthe like. Opposite the splice plate 8 there is a gusset plate 6 whichtakes the place of a splice plate on this side of the joint, but alsoextends between elements of the structural member 1" and is securedthereto by rivets 4. The plate 6 extends entirely through the member 1",being secured thereto on each side edge.

The splicing of the two parts of member 1 in the vertical plane isaccomplished by another gusset plate which extends entirely through themember 1 and is riveted thereto throught-he top and bottom flanges 2.Above the member 1 the gusset plate 5 extends through the verticalmember 1 and is riveted" thereto along both side flanges, as shown inFigure 2. It is also provided with lateral ears to which arepivotallyattached tie rods 9. Other tie rods 19 lying in a horizontal the twoparts plane are similarly attached to the gusset 6. The two structuralmembers 1 and 1 are joined by a gusset plate 7 which extends only intothose members and not through them, being riveted to them along one edgeas shown. This'plate 7 serves as the attachment means for the inclinedstructural member 1", through which it extends and to which it isriveted along two edges.

The channels 2 are, of course, rolled shapes and are obtained from therolling mill in standard lengths. The structural members may then be puttogether in standard lengths, also, with spacers 3 and rivets 4positioned at regular intervals. When, in assembling a frame work of anykind the spacers and rivets would interfere with a fitting, such as asplice plate or gusset plate, they can be very readily removed bydrilling through the rivet and breaking out the rivet shell whichremains. Of course, special lengths for special purposes with all neededrivet holes properly located can be made up from the rolled shapes wherethat method of procedure seems desirable.

While for airplane purposes I prefer structural members composed of fourchannel elements such as those shown in the drawing. such members beinghighly satisfactory where connections between members are to be made atright angles, nevertheless my invention may be carried out by the use ofany number of channels greater than two, and where connections at anglesother than right angles are to be made it will be found best to employ amember with such a number of channels as will produce joints separatedby the desired angles.

The interior surfaces of structural members formed according to myinvention can be readily inspected in all their parts, and thesesurfaces can be suitably treated when necessary as by'spraying withpaint or other materials which resist deterioration.

Having thus described m invention what I claim as new is:

1. In an airplane three structu'al members arranged with their axes eachperpend icular to the other two, said members each comprising t'ourelongated elements evenly spaced around the axial center of the memberand secured together with their adjacent edges spaced apart slightly,and means for .securing said three members together, eomprisirg threegusset plates each arranged at right angles to the other two and eachsaid gusset plate being mounted between 'two adjacent elements of onemember and two adj accnt elements of another member.

2. Inan airplane, a pair of structural members arranged at right anglesto each other. a third member extending diagonally toward the jointbetween the pair of members, said members each comprising four elongatedBlCll'lGIltS evenly spaced around the axial center of the member andsecured together with their adjacent edges spacedapart slightly, andmeans for securing said three members together comprising a gusset platemounted between two adjacent elements of one member and two adjacentelements of another member and extending diametrically throughtheintermediate member between, two sets of adjacent edges therein.

In testimony whereof, I hereunto afiix my signature.

CLIFFORD J. LEISY.

